She parked the BMW under an elm with at least some scattered surviving foliage and killed the engine. She was dressed as before, mostly in black, but had discarded the head scarf borrowed from Mirsaad. A few lights burned here and there and the flickering blue-green shadow play of television screens illuminated a few more windows, but given the two thousand or more people all living within a minute's walk of Fabia Shah, the place was deathly quiet. Just how the Dignity Patrols liked it, she supposed.

Caitlin waited ten minutes behind the X5's tinted glass, one of the Russian machine pistols within easy reach on the passenger seat. A couple of lights flicked out while she maintained her vigil, and one of the late-night TV addicts finally gave up and went to bed. Just after twelve-thirty she moved, holstering the automatic with its twin in the combat harness under her leather jacket and taking a set of lock picks from the small storage bin between the front seats. She set the car's defenses and stepped out onto the grass footpath, closing the door softly behind her. Less than a minute later she was through the front door of the block where Fabia had been living four years ago, and within another a minute she had picked the lock on the letter box bearing a small handwritten name tag: SHAH.

A gas bill and a flyer from a shoe shop personally addressed to Baumer's mother lay uncollected inside.

Caitlin took a few seconds to listen to the building, sending her finely honed senses out along hard echoing corridors, up stairwells, past doors secured by metal grilles. She faintly heard two babies crying and a couple deep in argument. A television droned on somewhere. Repeats of Star Trek dubbed into German to judge by the faint strains of the famous theme music she was able to hear.

But there appeared to be nobody moving about. Nobody lying in wait.

She glided up a set of stairs to her left, empty-handed but ready to go gunshot. On the third floor, she ghosted along the hallway until reaching the right door. Heavy steel bars protected the entrance, but the lock was a primitive arrangement, easily neutralized in about a minute and a half. The cheap hollow-core wooden door behind it took less than half that time, but it was still an anxious interlude, kneeling in front of the handle with a tension wrench and half diamond and hook pick, obviously up to no good.

She was glad to get through the locks and, after gently unlatching the front door, into the apartment. A short, darkened entry hall lay in front of her, with a doorway into a laundry and bathroom to her immediate left. She could smell detergent and the warm, almost comforting odor of tumble-dried clothes in there. Caitlin took a good two minutes to let her eyes adjust to the darkness. She had rejected the idea of using goggles for fear of being blinded should Fabia suddenly flick on a light.

It did not take long to begin picking shapes and objects out of the charcoal gray dimness. A pair of windows in a lounge room directly in front of her appeared to open onto an internal courtyard. She unholstered one of the machine pistols and fitted the long rubberized tube of the specially designed Reflex Suppressor. With the stock unfolded and resting against her armpit, she felt confident enough to move into the main area of the flat.

A small kitchen sat to the left, just beyond the laundry and looking out over a tiny open-plan living area. There were no more doors on that side and only one to the right. The bedroom. The assassin moved slowly, not even pushing dust motes in front of her. She controlled her breathing and allowed her senses to flow outward in a meditative technique she had learned while studying aikido in Japan. Rather than focusing attention down to a single point and letting the world fall away, she threw open the doors of all her senses and allowed everything to rush in. She could smell the meal Fabia had cooked for herself hours ago. Taste the spices at the back of her mouth. Hear a clock ticking and a woman breathing. Feel the thin, threadbare carpet beneath the soles of her boots. See all the depressing details of the flat's spartan furnishings and the slight phosphorescent glow of a small TV screen on a sideboard crowded with photo frames. She knew that if she took the time to inspect those photographs, she would almost certainly find in some of them, smiling and innocent, the younger face of the man who had raped her back in Noisy-le-Sec.

She ghosted forward.

One hand reached out for the door, and she carefully pushed it open, ready to shoot if necessary. Instantly she was struck by the scent of Baumer's mother. Cold cream. A harsh perfume. Soap. And perhaps an apple-scented shampoo. The woman's breathing did not falter. She snored slightly and ground her teeth together, but Caitlin could tell that she was truly asleep.

She swept the muzzle of the suppressor across the room, but there was nowhere for anybody to hide. Fabia had no room for walk-in cupboards or closets, and just a few outfits hung from a wooden clothes rack pushed up against one wall.

They were alone.

Caitlin shouldered the machine pistol and took a small one-use syringe from her jacket.

She uncapped the business end, flicked the chamber to force any air bubbles up, and squeezed off a small stream of liquid to clear them completely. She carefully crossed the floor to crouch by the bed and without preamble slid the syringe into the woman's neck, pressing down on the plunger. Fabia snorted and moaned slightly. She rolled away from Caitlin, forcing her to follow while she administered the last of the shot.

When she could depress the plunger no farther, she withdrew the needle and waited, more than a little relieved that Baumer's mother had not woken up. With a few minutes to wait before the drug took hold completely, she withdrew from the room and checked the rest of the apartment again, spending some time with her ear to the front door, listening to the corridor outside.

Nothing.

She approached the bedroom with much less stealth this time, walking in and sitting on the mattress next to her mark.

"Fabia," she said in a conversational tone, not too loud and softened with a hint of kindness. "Fabia, it's time to wake up."

The woman stirred and gulped air. She stopped snoring but didn't rouse herself.

"Fabia," Caitlin repeated. "Wakey wakey…"

Jesus, she thought, I've been in England too long.

"Fabia, wake up. We need to talk now. About Bilal. I need to find Bilal."

"Bilal? Is that you?"

"No, Fabia. I am a friend of Bilal's. I need to find him. He needs my help."

The woman appeared to struggle against unconsciousness, lifting her head from the pillow, blinking her eyes slowly. She groaned and spoke in a slurred voice.

"Too tired."

"I know you're tired, Fabia. Just tell me where Bilal is and you can sleep. Is he here? In Neukolln?"

"Bilal…"

Caitlin suppressed her frustration. Questioning a drugged subject was never ideal, but Fabia would not raise an alarm and would remember this encounter only as a dream in the morning.

"Fabia, I need to see Bilal. Where is your son? Where is Bilal? Do you know?"

"Tired…"

"Where is Bilal, Fabia? His friends need him. Where is Bilal?"

"Not here," the woman said, speaking so faintly that Caitlin had to lean forward.

"What did you say, Fabia? Is Bilal here? In Berlin?"

"Bilal is gone," she said as the drug broke down more of her defenses. "He's gone away."

"Where?" Caitlin asked, containing her impatience. "Where has Bilal gone?"

"America."

Caitlin's surprise was so total that she nearly missed the snick of the door latch in the entry hall.

Baumer was in America.

But where?

The question answered itself.

He had to be in New York.

And how many possibilities opened up from that, like a poisonous flower budding in the dark? Fabia Shah mumbled on about Bilal and America and somebody called Abu, possibly Abu Bakr Shah, her brother, as Caitlin recalled from the al Banna case history.